An essential part of building a CO2 dragster is having the right tools. Quality dragsters can be shaped from simple hand tools such as a coping saw, files, and a sharp knife. On the other end of the spectrum, an increasing number of classrooms are manufacturing race cars on CNC mills (a great way to experience the CAD/CAM process).
Instructions on this site assume that you have access to a scroll saw and drill press. Note that the building process is virtually the same when using hand tools.
Basic Tools
Wood rasp
Half-round wood file
Coping saw
Sandpaper
Ruler (or other measuring device)
Scissors
Spray paint
17mm dowel (400mm length)
Scale
Basic Tools
Power Tools (optional)
Band saw
Drill press
Belt/disc sander
Engraving tool with accessories
Carving tool set
Digital caliper
Designing a CO2 Racer
Before putting pencil to paper, consider these important points:
Are you required to follow a set of specifications?
Is your grade on this project dependent on the car’s performance or appearance?
What is most important to you: speed at any price, show-stopping good looks, or some combination of the two?
If you're in it for the speed, know that the following design factors have an enormous impact on performance: weight — the lighter, the better; aerodynamics — you want your car to cheat the wind; and rolling resistance — less is more!
Vehicle weight is a critical factor in competition. Because weight is an enemy of speed, the idea is to get the weight to the absolute minimum. Remember to weigh the car with all the wheels and hardware (axles, washers, screw eyes, and so forth).
Thumbnail Sketching
Thumbnail Sketches
Now is the time to get some of those race car design ideas — undoubtedly floating around in your head — on paper. The best way to start is with concept sketches, also known as thumbnail sketches. Thumbnails are small, quick sketches used by engineers and designers to rapidly communicate ideas. They should not be detailed or even carefully done.
Be sure to experiment with different ideas and be as creative as possible.
Design Sketching
On a clean sheet of paper, sketch your favourite design from the thumbnail sketches on a larger scale with more detail. Draw the top and side views.
Make light projection lines from one view to the other to help you locate axle holes and other features of your design. Show the location of hidden details (such as the cartridge hole) by using dashed lines.
Design Drawing
Are you required to follow a set of specifications?
If so, obtain the list of specs and read it. While doing so, look at your design sketch to see how each spec applies to your design.
You may find it necessary to take notes or even change your design.
Working Drawing
The working drawing is a precise, 1:1 scale drawing that describes your car and its features. Working drawings should have top and side, or profile, views.
An accurate working drawing is important for two reasons:
1) A copy of the working drawing serves as a template for rough-cutting your car blank.
2) You may be required to submit your working drawing. It will be part of your grade or even be scored for competition points
Prototyping
Prototyping involves the construction of a three-dimensional model of your design. In this case you can use a polystyrene body blank provided to build your prototype. Prototyping is a quick way to put your design ideas to test. It gives designers the opportunity to make changes if necessary before the final version is produced.
Making the Prototype
Cut out the top and side (profile) views from a copy of your working drawing. Then, carefully outline the views onto the polystyrene blank.
Free Hand Foam Cutter
Use a hot wire foam cutter to roughly shape the blank:
Turn the blank on its side and cut out the profile view first.
Fit the waste pieces and working piece together and secure them by wrapping two bands of masking tape around the assembly.
Set the blank assembly upright and cut out the top view. Note: The hot wire will not cut through the masking tape, so you’ll have to work around the tape. When ready, remove the tape and carefully cut those areas last.
If you haven’t already done so, remove the masking tape and discard all the waste pieces.
Expanded Styrofoam Prototype
Smooth the corners of your prototype with a sharp knife, the hot wire cutter, or sandpaper. Note: You may have limited success with sandpaper on polystyrene.
If you are happy with your design and it fits the specifications now you are ready to start construction of your Dragster construction
Check out
https://filebox.vt.edu/users/sfagg/Inventor/home.swfCO2 Dragsters and F1's
Tools for Race car Building
An essential part of building a CO2 dragster is having the right tools. Quality dragsters can be shaped from simple hand tools such as a coping saw, files, and a sharp knife. On the other end of the spectrum, an increasing number of classrooms are manufacturing race cars on CNC mills (a great way to experience the CAD/CAM process).Instructions on this site assume that you have access to a scroll saw and drill press. Note that the building process is virtually the same when using hand tools.
Designing a CO2 Racer
- Are you required to follow a set of specifications?
- Is your grade on this project dependent on the car’s performance or appearance?
- What is most important to you: speed at any price, show-stopping good looks, or some combination of the two?
If you're in it for the speed, know that the following design factors have an enormous impact on performance: weight — the lighter, the better; aerodynamics — you want your car to cheat the wind; and rolling resistance — less is more!Thumbnail Sketching
Be sure to experiment with different ideas and be as creative as possible.
Design Sketching
Make light projection lines from one view to the other to help you locate axle holes and other features of your design. Show the location of hidden details (such as the cartridge hole) by using dashed lines.
If so, obtain the list of specs and read it. While doing so, look at your design sketch to see how each spec applies to your design.
You may find it necessary to take notes or even change your design.
Working Drawing
An accurate working drawing is important for two reasons:
1) A copy of the working drawing serves as a template for rough-cutting your car blank.
2) You may be required to submit your working drawing. It will be part of your grade or even be scored for competition points
Prototyping
Making the Prototype
construction
Marking Rubric